Invader in Hawai‘i, the Queensland Longhorn Beetle
Acalolepta aesthetica, known as the Queensland Longhorn Beetle, is a wood-boring beetle that has recently emerged as a problematic invader on the Hawai‘i Island. We are determining its current range and identifying patterns of host tree use, focusing on culturally important and native trees.
Overview:
New non-native species often pose a set of common challenges: poorly defined patterns of distribution and abundance, unknown impacts, and few established methods for monitoring and control. The Queensland Longhorn Beetle - QLB - exemplifies these challenges and has raised substantial management concerns because longhorn beetles can cause substantial economic and ecological damages.
The invasive QLB population is centered on the eastern side of Hawaiʻi Island, with populations spreading within and out of the Puna District. Larval feeding behavior damages and can kill host trees. Documented hosts include agricultural species such as cacao and citrus, ornamental cycads, and culturally important kukui and ʻulu trees. Documentation of additional hosts is ongoing by the Hawaiʻi Department of Agriculture (HDOA). Patterns of host tree preference are poorly known.
There are currently no known effective lures for monitoring the species, but the species’ impacts make visual surveys of host trees possible. Sap oozes from infestation sites, larvae push out frass - making genetic confirmation of species identity possible - and exit holes can be seen in tree trunks and large branches.
Objectives:
We are mapping the current distribution of QLB on Hawai‘i Island and identifying patterns of host tree use. This will provide a baseline for research, monitoring, and management.
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Contact landowners and conduct surveys on infested properties to quantify the host preferences of QLB.
-
Survey preferred hosts across a broader landscape to determine the extent of the invasion and quantify rates and patterns of QLB spread. Develop an approach that could serve as a useful model for other rapid response efforts.
-
Evaluate threats posed by QLB to native species by conducting no-choice oviposition tests in the lab. A no-choice oviposition test evaluates whether a fertile female beetle will lay an egg on a given host plant when no other host is available; we are also tracking larval survival on different hosts.
Acalolepta aesthetica, known as the Queensland Longhorn Beetle, is a wood-boring beetle that has recently emerged as a problematic invader on the Hawai‘i Island. We are determining its current range and identifying patterns of host tree use, focusing on culturally important and native trees.
Overview:
New non-native species often pose a set of common challenges: poorly defined patterns of distribution and abundance, unknown impacts, and few established methods for monitoring and control. The Queensland Longhorn Beetle - QLB - exemplifies these challenges and has raised substantial management concerns because longhorn beetles can cause substantial economic and ecological damages.
The invasive QLB population is centered on the eastern side of Hawaiʻi Island, with populations spreading within and out of the Puna District. Larval feeding behavior damages and can kill host trees. Documented hosts include agricultural species such as cacao and citrus, ornamental cycads, and culturally important kukui and ʻulu trees. Documentation of additional hosts is ongoing by the Hawaiʻi Department of Agriculture (HDOA). Patterns of host tree preference are poorly known.
There are currently no known effective lures for monitoring the species, but the species’ impacts make visual surveys of host trees possible. Sap oozes from infestation sites, larvae push out frass - making genetic confirmation of species identity possible - and exit holes can be seen in tree trunks and large branches.
Objectives:
We are mapping the current distribution of QLB on Hawai‘i Island and identifying patterns of host tree use. This will provide a baseline for research, monitoring, and management.
-
Contact landowners and conduct surveys on infested properties to quantify the host preferences of QLB.
-
Survey preferred hosts across a broader landscape to determine the extent of the invasion and quantify rates and patterns of QLB spread. Develop an approach that could serve as a useful model for other rapid response efforts.
-
Evaluate threats posed by QLB to native species by conducting no-choice oviposition tests in the lab. A no-choice oviposition test evaluates whether a fertile female beetle will lay an egg on a given host plant when no other host is available; we are also tracking larval survival on different hosts.